Contents

1 Definition

The skeletal muscles comprise the muscles that are fixed to the skeleton or - in a broader sense - that are responsible for the movements of the body. Just as the myocardium, they belong to the striated muscles.

Furthermore, you differentiate between the origin of the muscle and the muscle insertion, which has a "sinewy" or "fleshy" connection to the bone. A skeletal muscle can have several surfaces of origin - also at various bones.

Another macroscopic characteristic of the skeletal muscles is their pennate structure. You can differentiate between simple and double pennate muscles.

2.2 Functional anatomy

The skeletal muscles can also further be divided according to functional or biomechanical aspects. Regarding the interaction of muscles, you can differentiate between:

2.4 Histology

A skeletal muscle consists of the actual muscle fibers, which are responsible for the contraction, and supportive tissues. On their exterior, the skeletal muscles are covered by a layer of coarse connective tissue, the fascia. From there, some connective tissue offshoots draw into the muscle, which further divide it into fiber groups. They are also called septa. Thus, a muscle can be divided into several hierarchical functional units, whereof the sarcomer is the smallest functional unit of the muscle.

The layers of connective tissue that surround the muscle fibers or fascicles unite ate the muscle heads into the tendons of the muscle, which insert on the bone. They also contain the nerves and blood vessels that supply the muscle.

The main components of the skeletal muscles are the contractile proteins actin (3% of the total weight of the skeletal muscle) and myosin (7% of the total weight of the skeletal muscle), as well as the Z-lines, which are connected to the actin fibers. The distance between the Z-lines is called sarcomere. Around 100mg per gram of skeletal muscle represent the contractile proteins.